1. Field of Invention
This invention generally relates to a toy construction set, and specifically to a set of building blocks that connect by magnetic force to each other in both horizontal and vertical directions. The construction set provides the user with a means to build three dimensional structural designs and promotes creativity, education and entertainment.
2. Related Inventions
Previously, other types of construction blocks have been designed to connect magnetically, but none have the advantages in design as stated in the present invention.
There are previous block designs where the connecting faces are smooth and flat, and the connection is made by a single magnet located behind the surface of the face of each block, such as indicated in U.S. Pat. No. 3,601,921.
The first disadvantage of this design is the difficulty involved in achieving a precise alignment of the matching block surfaces. The smooth surface faces are without a guiding means to aid in alignment of the blocks. A guiding means might involve protrusions on the face of one block to match up to recesses on the joining face of another block. Without precise alignment in this block design, the structure constructed lacks stability and visual symmetry.
The second disadvantage of this design is the direct magnet to magnet type of connection. To make this connection, the north polarized side of a magnet connects to the south polarized side of another magnet. Blocks of this design type would require some faces to be north polarized and some to be south polarized. The magnetic polarity of the block face may not be readily apparent to the user by simply looking at each block. Therefore, the user would have to spend time hunting for block faces with opposing polarities, thereby wasting playtime and increasing frustration.
The third disadvantage of a block design where the magnets are located behind the block surface is the impediment provided by the intervening material that separates the two magnet surfaces. The intervening material reduces the attractive force between the two magnets such that the bond between blocks is weaker than if there would be direct contact of the magnets.
The fourth disadvantage of a magnet to magnet connection on smooth faces is the likelihood of unintentional rotation of the blocks along the plane of connection. The connection of a single magnet on one block face to a single magnet on another block face allows the two faces to rotate relative to each other. Similar to the lack of a guiding means, the rotation results in imprecise alignment of the blocks, and the structure becomes less rigid and unstable.
Some construction blocks have been designed with a means to allow the magnets to rotate within the blocks, so that polarity is not an issue: U.S. Pat. Nos. 5,746,638 and 6,749,480; U.S. applications No. 2005/0164595 and No. 2006/0111010. However, these inventions employ various design features which add unnecessary complication and expense to the toy's fabrication. These designs also lack a guiding means to achieve precision in block alignment, and allow for rotation of the blocks along the plane of connection.
There are block designs were the magnets are located only in two parallel opposing faces, whereby the user is restricted to joining blocks magnetically in only one plane, either horizontally or vertically. This design limits the versatility and types of structure that can be assembled with the blocks.
U.S. Pat. No. 6,024,626 is a design for magnetic blocks that uses four points of magnetic connection on each of two parallel opposing faces, and employs a center protrusion with matching recess for positioning and aligning the blocks. The four magnet surfaces are located behind the block face. The design uses magnet to magnet connections which burden the user with searching for opposing polarity of the block faces. The hidden magnet design introduces intervening material that obstructs and reduces the magnetic force available to connect the blocks. In addition, with only two opposing block faces available for connection, the block design restricts the user to either horizontal or vertical connection, and therefore limits the assembly and creative scope of the structure.
There exists a magnetic construction set that uses blocks with a positioning means and larger, more powerful magnets to make magnetic connections to assemble specific structures. While this type of design allows for non-rotation of the blocks and more stable structures, the high level of magnetic force exhibited presents a safety issue when used in the design of children's toys. The high level of force involved presents a means for a child's fingers or skin to become pinched between the blocks during assembly. In this design, the magnets are not adequately attached to their supporting structure. Therefore, larger, more powerful magnets can detach from their recesses, presenting a serious health concern if ingested. Typically, the blocks in such a set also have magnets on only two opposing faces, which present a polarity issue, and restrict construction to only horizontal or vertical directions. In addition, these construction sets are typically designed for assembly of specific structures; therefore, the blocks are not versatile enough to allow for creative reuse in assembly of a variety of structures.